RELENG_7 jerky mouse and skipping sound

[[LoN]Kamikaze]

[LoN]Kamikaze wrote:
> Anish Mistry wrote:
>> I just updated to RELENG_7 from 6.2 and I'm running into some really 
>> annoying issues with jerky mouse movement and skipping sound.  This 
>> seems to be similar to:
>> Re: SCHED_4BSD in RELENG_7 disturbs workflow
>> This happens both with 4BSD and ULE.
>>
>> I seems to happen when I'm compiling ports and a new cc/bzip2/sh 
>> process fires off (I'm just watching top), I'll get the 
>> skip/freezeup.
>>
>> This behavior is pretty pronounced, as I'm installing gutenprint right 
>> now...
>
> 2 things fixed it for me:
> Using SCHED_ULE and rebuilding x11-drivers/xf86-input-mouse.

It turned out my report of success was wrong. However I think I cornered the
problem. The following lines are two snippets of xev output:

KeymapNotify event, serial 28, synthetic NO, window 0x0,
    keys:  69  0   0   0   0   0   0   0   0   0   0   0   0   0   0   0
           0   0   0   0   0   0   0   0   0   0   0   0   0   0   0   0

ButtonPress event, serial 28, synthetic NO, window 0xe00001,
    root 0x145, subw 0x0, time 2952962341, (21,177), root:(1649,206),
    state 0x0, button 1, same_screen YES

Both events are the result of pressing the left mouse button. Sometimes the
first, sometimes the second message appears. So it seems that Xorg has trouble
with /dev/sysmouse. If I omit moused and configure X to take the mouse from
/dev/ums0, everything seems to be fine. The same, if I opperate without a mouse.